This invention relates generally to medical diagnostic ultrasonic imaging techniques, and in particular to such imaging techniques that provide multiple images displayed in sequence, wherein each image is associated with a respective phase of a physiological cycle.
U.S. Pat. No. 6,014,473, filed Aug. 22, 1997, discloses a system for collecting single frames of image data from each of a plurality of spatial locations. Tracking information is collected with each frame, and this tracking information is used to assemble the frames into a static three-dimensional image or an extended field of view image. In three-dimensional imaging, the transducer probe is swept across a three-dimensional volume, and the tracking data is obtained along tracking planes oriented generally transverse to the image planes. In extended field of view imaging, the transducer probe is maintained within a plane such that multiple image frames are obtained in the same plane. The tracking information is then used to reconstruct an extended (typically elongated) field of view from multiple ones of the coplanar images. In both cases, the three-dimensional image or the extended field of view image is a static image. The entirety of the above-identified U.S. Pat. No. 6,014,473 is hereby incorporated by its reference for its teaching of techniques for forming three-dimensional images and extended field of view images.
It is also known to acquire image frames from a particular part of the cardiac cycle. This can be done by triggering image acquisition at a specified time duration after a particular feature of the ECG signal, such as the R wave.
The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on these claims.
A medical diagnostic ultrasonic imaging method for generating a multiple image sequence includes acquiring a sequence of medical ultrasonic image frames. This sequence includes Ci frames in each ith period of a physiological cycle such as the cardiac cycle. An integer N is selected based on a function of selected values of Ci, e.g., maximum, minimum, average, median. At least one image frame is added to a portion of the sequence characterized by fewer than N frames per physiological cycle, and/or at least one image frame is removed from a portion of the sequence characterized by more than N frames per physiological cycle. Preferably, a cluster technique is used to determine the average physiological cycle period.